After running his nutritional products company Naturhouse Health SAU from Barcelona for at least 25 years, Revuelta last month moved the firm’s headquarters to Madrid. The Naturhouse chairman was concerned about an unconstitutional referendum on independence that separatists plan to hold on Oct. 1, disregarding rulings of the Spanish courts.

“Business needs legal security,” Revuelta said in an interview. “Tension has been growing within Catalan society and between Catalan society and the rest of the country.”

Naturhouse is not the only company alarmed at developments in Spain’s biggest regional economy. Some U.S. firms who based their Spanish operations in Barcelona have prepared plans that would allow them to withdraw from Catalonia overnight if it secedes, said Jaime Malet, Chairman of the American Chamber of Commerce in Spain.

“People do not to like to invest in places where there are problems,” he said by phone.

Constitutional Crisis

Catalonia’s campaign to break away from Spain has become a constitutional crisis as Spanish Prime Minister Mariano Rajoy uses the full force of the law to try to stop the illegal vote. After Catalan President Carles Puigdemont passed his referendum bill last week, Spanish prosecutors filed criminal charges against the separatist leaders and ordered their officials in the region to question any local mayors helping to organize the ballot.

The legislation, which has been suspended by Spain’s Constitutional Court, would allow the assembly to declare independence within 48 hours of a “yes” vote with no minimum turnout needed to make the result binding.

Malet said his personal view is that Rajoy has enough legal weaponry to ensure Catalonia’s bid for independence goes nowhere. Opinion polls also show support for secession has been falling over the last four years as the economic recovery draws moderate voters away from the cause. Even so it makes sense for company boards to have the paperwork in place so that they can move within 24 hours if necessary, said Malet.

Jaime Guardiola, CEO of Banco Sabadell SA, based near Barcelona, said that although he’s seen few companies following Naturhouse’s lead so far it would make sense for executives to be preparing contingency plans, according to a report by Efe. Economy Minister Luis de Guindos, however, played down the risk.

“There haven’t been any significant moves,” de Guindos said Wednesday in televised comments, adding that it would be “irrational” to think secession could happen.

Market Flutters

So far investors have taken a relatively sanguine attitude to the risk of a split. Though the spread that investors charge to hold 10-year Spanish debt instead of German bonds has widened by 24 basis points to 118 since the start of August, that’s still in line with its average for the year.

Even so, Moody’s Investors Service said in a Sept. 11 report that the recent escalation in tensions was negative for credit even though it also expects the region to remain part of Spain.

“Markets until recently have refused to consider Catalonia risk,” said Lorenzo Bernaldo de Quiros, president of Freemarket Corporate Intelligence, a Madrid-based consulting firm. “But investors who don’t factor that in are going to find themselves exposed.”

Revuelta said one of the reasons he decided to move Naturhouse’s head office to Madrid was his concern about the legal instability that a disputed secession would trigger. He said the company already directions most operations from Madrid and that is where the board meets.

The company has sales of almost 100 million euros ($120 million) a year and runs 2,400 stores in 33 countries. The first Naturhouse store opened in Spain’s Basque region in 1992.

Even if the consensus is right and the separatists are heading down a dead end, the confusion that their campaign has generated is already adding a headache for international companies like Volkswagen AG, Procter & Gamble Co. and DowDuPont Inc. with operations in the region. Just getting head office to understand what is happening is getting harder and harder.

“This situation has already lasted so long,” said Malet. “It’s a major challenge to explain to American investors and investors in other countries what is actually going on.”